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At least 19 recordsLinked to original sources
PubMed1978

New cephalosporins with 7-acyl groups derived from beta-ketoacids. II. Further modifications of 7-(3-oxobutyrylamino)-cephalosporins.

New cephalosporins modified in the acyl part of 7-(3'-oxobutyrylamino)cephalosporins (1), which have been described in the preceding paper, were synthesized by thiolation at the 2'- or the 4'-position, or by transforming the 3'-oxo group into a 3'-imino group. The most active compound in vitro was 3-[[(1-methyl-1H-tetrazol-5-yl)thio]methyl]-7-(4-methylthio-3-oxobutyrylamino)ceph-3-em-4-carboxylic acid (7c), which showed superior in vitro activity against Gram-positive and Gram-negative bacteria compared to the parent cephalosporin (1b) with the same 3-substituent. The ED50 value for 7c, however, was essentially equal to that of 1b in mice infected with Escherichia coli O-111.

Animals↗
PubMed1979

Chemical reactions in cephalosporin allergy: high-pressure liquid chromatographic analysis of cephalosporin aminolysis kinetics.

Cephalosporin reaction with protein amino groups is fundamental to cephalosporin allergy. Cephalothin and cefazolin reaction kinetics with epsilon-aminocaproic acid, B-alanine, and glycine in aqueous solution were investigated. All reactions were conducted at 35 degrees and 0.5 ionic strength and were followed by ion-exchange high-pressure liquid chromatography. The aminolysis rate constants can be expressed as terms representing uncatlyzed or water-catalyzed amine reaction, self-assited nucleophilic reaction, and hydroxide-ion-catalayzed nucleophilic amine attack on the beta-lactam moiety. Cephalothin and cefazolin react with amines as readily as penicillin G. The UV spectra of several cephalothin-glycine reaction products were recorded, and their possible structures are discussed.

Amines↗
PubMed1979

In vitro and in vivo laboratory studies on three hydroxyiminophenylacetyl cephalosporins with particular reference to SK&F 80303, an unusually long-acting cephalosporin.

Three cephalosporins with 7-(2-hydroxyiminophenylacetamido) side chains (SK&F 79433, 80000 and 80303), differing in their 3-substituents, exhibited similar broad-spectrum antibacterial activity in vitro against strains of Staphylococcus aureus, Streptococcus faecalis and various Gram-negative bacilli. All three were active in vivo (s.c., mouse) against S. aureus, Escherichia coli or Klebsiella pneumoniae, but they differed significantly in serum pharmacokinetic profiles. SK&F 80303 produced high and extremely prolonged serum levels and protected mice when administered up to 24 hours prior to challenge with beta-lactamase-producing S. aureus or K. pneumoniae. It was resistant to hydrolysis by beta-lactamases from S. aureus, and variably so to beta-lactamases from E. coli strains. SK&F 80303 was bacteriolytic to logarithmically growing S. aureus, E. coli, Proteus mirabilis, K. pneumoniae and Enterobacter cloacae (partially). SK&F 80303 illustrates further the effect of the 3-sulfoalkyltetrazole substituent on the pharmacokinetic properties of cephalosporins. Its combined biological properties make it a possible candidate for therapeutic and long-term prophylactic use.

Animals↗
PubMed1979

New cephalosporins and 7 alpha-methoxy cephalosporins. Chemistry and biological activities.

The synthesis and the in vitro activity of a number of cephalosporins and 7 alpha-methoxy cephalosporins having 7-acyl substituents derived from 1-methyl-4 (or 5)-nitro-1H-imidazolyl-thioacetic acids are described. The microbiological profile is influenced by the position of both the nitro group and the side-chain sulfur atom on the 1-methyl imidazole, and by the nature of the 3-substituent.

Bacteria↗
PubMed1979

Electronic structures of cephalosporins and penicillins. 9. Departure of a leaving group in cephalosporins.

Molecular orbital calculations by the CNDO/2 method are used to study the potential energy surface for the stretching and rupturing of the CH2-OAc bond in a model cephalosporin structure, 7-amino-3-(acetoxymethyl)-3-cephem. The bond is easier to stretch and break when a nucleophilic group is in the vicinity of or attached to the beta-lactam carbonyl carbon (C8). The rate of acylation by a beta-lactam antibiotic at the receptor sites in bacterial cell-wall enzymes will be enhanced by a suitable leaving group at the 3' position. An orientational specificity is predicted for the direction of departure of the leaving group. Regardless of the direction the nucleophile approaches C8, the CH2-OAc bond is easiest to break when the acetate group departs from the alpha face of the molecule.

Cephalosporins↗
PubMed1979

Antibacterial activity of ceftizoxime (FK 749), a new cephalosporin, against cephalosporin-resistant bacteria, and its stability to beta-lactamase.

Antibacterial activity of FK 749 against ampicillin-resistant clinical isolates of Escherichia coli was compared with those of other newly developed cephalosporins. FK 749 was the most active against strains possessing R-plasmids specifying ampicillin resistance and those whose resistance was chromosomally determined. The susceptibility of ampicillin-susceptible E. coli to FK 749 was not decreased by transduction of ampicillin resistance-specifying plasmids. However, most of the transconjugants acquired a high level of resistance to cefoperazone and cefamandole and a moderate level of resistance to cefoperazone and cefamandole and a moderate level to cefotiam. FK 749 was highly stable to both penicillinase- and cephalosporinase-type beta-lactamases, including R-plasmid-mediated beta-lactamase. Its level of resistance to beta-lactamases was comparable to those of cefoxitin, cefmetazole, and cefotaxime, slightly superior to that of cefuroxime, and much superior to those of cefotiam, cefamandole, and cefoperazone.

Ampicillin↗
PubMed1979

Comparison of antibacterial activity of a new cephalosporin, ceftizoxime (FK 749) with other cephalosporin antibiotics.

FK 749 is a distinctive new parenteral cephalosporin antibiotic with a broad antibacterial spectrum which is more potently active against a wide variety of Gram-negative bacilli, including the opportunistic pathogens such as Citrobacter and Enterobacter species and Serratia marcescens, than SCE 963, T 1551 and cefmetazole. The activity of FK 749 against Escherichia coli, Klebsiella pneumoniae, pyogenes was by far superior to that of the three other antibiotics. These test organisms were not resistant to FK 749. The antibacterial activity of FK 749 against Pseudomonas aeruginosa was almost the same as that of ticarcillin but was inferior to that of gentamicin and T 1551. The bactericidal activity of FK 749 against E. coli, K. pneumoniae and Proteus mirabilis was more potent than that of the three other antibiotics. FK 749, like cefmetazole, was extremely stable to beta-lactamases. In studies in mice, the therapeutic effect of subcutaneous injection of FK 749 against various infections due to Gram-negative bacilli was by far superior to that of SCE 963, T 1551 and cefmetazole, was almost the same as that of SCE 963 and cefmetazole against Staphylococcus aureus infection and that of ticarcillin against P. aeruginosa infection.

Ampicillin↗
PubMed1978

Immunologic cross-reactivity between penicillins and cephalosporins: a review.

Several approaches have been undertaken in the study of possible immunologic cross-reactivity between cephalosporins and penicillins. Although the chemical structures of these compounds are similar in several respects, there are distinct differences in their degradation and transformation. Various degrees of cross-reactivity of antibodies produced in response to administration of these drugs have been demonstrated both with test systems that measure IgG and IgM antibodies and with those that measure IgE antibodies. The clinical significance of immune responses to cephalosporins is best understood in regard to immunohematologic abnormalities: positive direct antiglobulin (Coombs') tests occur in only approximately 3% of patients receiving cephalosporins; however, several cases of cephalosporin-induced immune hemolytic anemia have been reported. Clinical studies of the cephalosporins indicated that patients with a history of penicillin allergy have increased incidence of reactivity to cephalosporins, but it is impossible to determine to what extent this finding is due to immunologic cross-reactivity because penicillin-allergic patients have an increased incidence of hypersensitivity reactions to drugs immunologically unrelated to penicillins. In addition, there is evidence of specific immune response to cephalosporins that indicates independently acquired hypersensitivity rather than cross-reactivity in some patients.

Anemia, Hemolytic, Autoimmune↗
PubMed1979

Inactivation of cephalosporins by Bacteroides.

We investigated the relationship between beta-lactamases of Bacteroides fragilis organisms and their resistance to cephalosporins. Timed killing curves were used to study the in vitro activity of three cephalosporins, cephalothin, cefazolin, and cefamandole, and a semisynthetic cephamycin, cefoxitin. Measurements of residual antibiotic concentrations in culture supernatants were made, and they were compared with the beta-lactamase activity of the microorganism. A cephalosporin-susceptible strain was rapidly killed by cephalothin, cefazolin, cefamandole, and cefoxitin. Four cephalosporin-resistant strains were not killed by cephalothin, cefazolin, or cefamandole but were killed by cefoxitin. An inoculum effect was noted with cefazolin and not with cefoxitin. The resistant strains of Bacteroides inactivated the three cephalosporins, but there was no inactivation of cefoxitin. A constitutive beta-lactamase was detected in all the isolates of the B. fragilis group that were resistant to the cephalosporins. There was no distinction of the species based on isoelectric focusing of the enzyme. These data suggest that inactivation by beta-lactamase may be the mechanism for resistance of B. fragilis to the cephalosporins and would explain the enhanced in vitro activity of cefoxitin.

Bacteroides↗
PubMed1979

The comparative beta-lactamase resistance and inhibitory activity of 1-oxa cephalosporin, cefoxitin and cefotaxime.

The beta-lactamase stability and inhibitory activity of 1-oxa cephalosporin, (6R,7R)-7-[[carboxy(4-hydroxyphenyl)acetyl]amino]-7-methoxy-3-[[(1-methyl-1H-tetrazol-5-yl)thio]methyl]-8-oxo-5-oxa-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, was investigated and compared to that of cefoxitin and cefotaxime. There was no detectable beta-lactamase hydrolysis of 1-oxa cephalosporin, cefotaxime and cefoxitin when incubated with beta-lactamases of plasmid or chromosomal origin which were primarily cephalosporinases or enzymes which hydrolyzed both penicillins and cephalosporins. The beta-lactamase inhibitory activity of 1-oxa cephalosporin was comparable to that of cefoxitin and cefotaxime. At equal molar concentration of substrate and inhibitor, cefoxitin, cefotaxime and 1-oxa cephalosporin effectively inhibited cephalosporinase hydrolysis of cephaloridine. Cefoxitin and cefotaxime were more effective inhibitors than the 1-oxa cephalosporin against a Providencia enzyme, whereas cefotaxime and 1-oxa cephalosporin were more effective inhibitors of a Citrobacter cephalosporinase.

Bacteria↗
PubMed1976

Comparative in vitro activity of cephalosporins.

The in vitro activity of cephalexin, cephaloridine, cephalothin, cephapirin, cefoxitin, cephamycin C, cepharadine and cefazolin was determined against 443 isolates of bacteria. At a concentration of 12.5 mug/ml, all of the cephalosporins inhibited more than 60% of the isolates of Klebsiella pneumoniae. At the same concentration, cephalexin, cephaloridine, cephalothin, cephapirin, cephamycin C and cefazolin inhibited more than 90% of isolates of proteus mirabilis. All of the cephalosporins except cephalothin and cephapirin inhibited over 60% of isolates of Escherichia coli at a concentration of 12.5 mug/ml. Cefoxitin was the most active cephalosporin against gram-negative bacilli. There was substantial differences in the activity of cephalosporins against gram-positive cocci. Cephaloridine was the most active cephalosporin against these organisms. There was considerable fluctuation in the proportion of isolates of gram-negative bacilli susceptible to these cephalosporins from year to year, but there was no evidence to suggest that the number of resistant isolates was increasing.

Cephalosporins↗
PubMed1979

[Comparative study of the distribution of semisynthetic cephalosporins in the body of rats].

Distribution of 6 cephalosporin antibiotics, i. e. cephaloridin, cephalotin, cephradin cephacetryl, cephazolin and cephapyrin for parenteral use was studied comparatively on rats. The studies showed that all the above cephalosporins were well absorbed into the blood after intramuscular administration. The highest serum levels were achieved with the use of cephozolin. Still, its levels in the animal organs were mainly not higher and sometimes even lower than those provided by the other antibiotics. The highest levels of cephalosporins were detected in the kidneys. Cephalotin, cephapyrin and cephacetryl differed by the character of their distribution in the rats from the other 3 antibiotics: the levels of cephalotin and cephapyrin in the heart, spleen and muscles were lower than those of the other cephalosporins; sometimes they were even not detected in these organs; cephacetryl was not found in these organs. The levels of these 3 antibiotics in the kidneys were lower than those of the other cephalosporins. Cephalotin, cephacetryl and sometimes cephapyrin were not detected in the rat liver. None of the cephalosporins was found in the brain tissue.

Animals↗
PubMed1978

Pharmacokinetics of cephalosporins in patients with normal or reduced renal function.

The pharmacokinetic distribution of 10 cephalosporin compounds, cephalothin, cephaloridine, cephaloglycine, cephalexin, cefazolin, cephapirin, cephradine, cephacentrile, cefoxitin, and cefamandole, in patients with various degrees of renal function was reviewed. The mean serum half-life (t1/2) of each cephalosporin compound was calculated from reported data in patients grouped according to their degree of renal function, as determined by the rate of creatinine clearance. Mean t1/2 values in patients with normal renal function were compared with t1/2 values for the same cephalosporin in patients with moderate renal failure and severe renal azotemia. The effect of hemodialysis and peritoneal dialysis on the mean serum t1/2 of each cephalosporin was also determined. The mean serum t1/2 of each cephalosporin progressively increased as the rate of creatinine clearance decreased. Hemodialysis decreases the t1/2 of cephaloridine, cephalexin, cefazolin, and cephacetrile but only minimally influences the t1/2 of cephalothin and cefamandole. Peritoneal dialysis reduces the t1/2 of cephalothin and cephaloridine but only minimally influences the t1/2 of cefazolin and cefamandole.

Cephalexin↗
PubMed1979

Comparison of activity and beta-lactamase stability of cefotaxime with those of six other cephalosporins.

A study of the susceptibility to cefotaxime and six other cephalosporins in 213 nonselected strains of nine different bacterial species clearly showed that cefotaxime was the most active against aerobic gram-negative bacilli. The same pattern emerged with 84 cephalothin-resistant strains of five enterobacterial species, but the mean minimal inhibitory concentration values for all cephalosporins were about twofold higher in this group of strains. Cephalothin was the most active antibiotic against Staphylococcus aureus. The inoculus effect of 10 cephalothin-resistant strains was relatively small, but it was most marked for cefamandole, as compared with that of three other new cephalosporins, including cefotaxime. The susceptibility of these cephalosporins to beta-lactamases from 12 beta-lactamase-producing enterobacterial strains was determined. Half of these were slightly active against cefotaxime and had similar activity against cefuroxime. Cefoxitin was not degraded at all, and cefamandole was the most susceptible. No correlation between beta-lactamase susceptibility and minimal inhibitory concentration values of different cephalosporins was found. Cefotaxime combined high intrinsic antibiotic activity with marked resistance to beta-lactamase inactivation.

Bacteria↗
PubMed1978

Suppression of lymphocyte responses by cephalosporins.

Human peripheral blood lymphocytes were cultured in several concentrations of each of several cephalosporins. Responses to phytohemagglutinin were compared with that of duplicate cultures containing penicillin-streptomycin, chloramphenicol, or no antibiotics. Possible effects of cephalosporins on responses of lymphocytes to concanavalin A and pokeweed mitogen were similarly determined. Significant suppression of responses to phytohemagglutinin and concanavalin A were seen in cultures containing 50 microgram each of cephalothin, cephalexin, or cephradine per ml. Lymphocyte responses to pokeweed mitogen were suppressed by 50 microgram of cephalexin, cephradine, or cefoxitin per ml. A higher concentration (100 microgram/ml) of all cephalosporins except cefoxitin and cefazolin suppressed the phytohemagglutinin response to less than 20% that of controls. Chloramphenicol (50 microgram/ml) did not inhibit the response to any mitogen used. These findings suggest that cephalosporins should not be used for prevention of bacterial overgrowth in certain cell cultures. Since many of the cephalosporins were suppressive in therapeutically attainable concentrations, these results may have potential clinical significance.

Cephalosporins↗